I wouldnt recommend buying something like a dell and then ripping out componenets and replacing them, firstly this voids the warrenty, which is alot of what you pay for. Secondly,whats the point? I would just buy a barebones syetm off of newegg, these usually include a case, motherboard, processor, ram, and powersupply. Then you buy the other componetens like videocard, mouse, keyboard etc. Newegg.com is the place you should probbaly get all of your components, they have great prices and customer service. If you need any advice on what parts to buy just ask!